Make the save dialog an actual dialog

Major changes:
* Create a MW specific save dialog class
* Widgetize save dialog elements
* Simplification of viewPageTarget

Minor changes:
* Added getWindow method to windowSet and setTitle methods to window class
* Add transition css properties to dialog styles

Bug: 48566
Bug: 50722
Bug: 51918
Bug: 52175
Bug: 53313
Change-Id: I8c0db01fb8477a9b3d3dfe2a6073ac67869ce40e